John booth



(No Model.)

J. BOOTH.

SLIDE VALVE.

No. 339,734, v Patented Apr. 13, 1886.

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UNITED STATES PATENT ()FFICE.

JOHN BOOTH, OF INDIANAPOLIS, INDIANA.

SLI DE=VALVE.

SPECIFICATION forming part of Letters Patent No. 339,734, dated April 13,1886.

Application filed September 14, 1885. Serial No. 177,017. (No model.)

To aZZ whom it may concern:

Be it known that 1, JOHN BooTH,a citizen of the United States, residing at Indianapolis, in the county of Marion and State of Indiana, have inventedanew and useful Improvement in Slide-Valves for Steam-Engines, of which the following is a specification.

My invention relates to improvements in slide-valves for steam-engines; and the objects of my improvements are to relieve the surface of the valve from the friction consequent on the difference of pressure between the back of the valve and the cavity of the exhaust or eduction passage. This I attain by means of construction as illustrated in the accompanying drawings, in which-- Figure l is a top view of the valve and steam-chest with the cover removed; Fig. 2, a vertical longitudinal section through the center. Fig. 3 is. a front end elevation of the valve; Fig. 4, a vertical transverse section of the valve through the line 1 2.

Similar characters of reference apply to similar parts in the several views.

A is the slide-valve; B,the equalizing frame or ring; O,the elastic packing; D, the packing frame or ring. E E are the packing-springs. F F, &c., are the steam-vents. His the valveyoke; I, the valve-rod; J, the steam-chest; K, the valve-seat. L L are the steam-induction ports. M is the steam exhaust or eduction port. N is the steam-chest cover; 0, the exhaust-pipe. a a, &c., are the steam chest bolts; 0, the packing-groove.

The mode of constructing and operating my improved valve is as follows: The valve A in external outline is a plain rectangular body of dimensions suitable to the inductionports L L, and is enveloped by the yoke H, to which is attached the valve-rod I, by which the valve is operated. The exhaust or eduction cavity extends through the whole depth of the valve. The packing-groove cis formed in the walls of the valve between the outside and the exhaust-cavity. The equalizing frame or ring 13 is fitted to the packing-groove 0, and

extends above the top of the valve A, with an outside dimension corresponding to the valve. The packing frame or ring D is fitted to the groove 0, and is supported by the packingsprings E E and sustained above the steamvents F F, &o. ,which admit the steam and press the frame D toward the equalizing-frame B. The space between the equalizing-frame B and the packing-frame D is filled by a body of fibrous material-such as asbestus-as will retain its elastic properties without deterioration from the action of the heat of the steam. By the pressure of the steam acting on the packingframe D and compressing the packing material C O the steam cannot escapebeyond the equalizing frame or ring B, and it is consequently forced outward against the steam-chest cover N, thereby making the upward-pressed surface of the equalizing-frame B equal to the downward-pressed surface of the valve A, minus the area of the space between the packing-groove c and the outside of the walls of the valve A, thus leaving a preponderance of pressure in favor of the valve to secure its adherence to its seat K.

' The packing frame or ring B can be made of a circular form and the packing-groove in the back of the valve made to conform thereto;or it can be made of a rectangular shape and correspond to the shape of the ordinary slidevalve.

I do not claim the equalizing frame or ring B, the grooved-back valve A, the springs E E, nor the steam-vents F F, Ste.

What I claim, and desire to secure by Letters Patent of the United States, is-

In a slide-valve of a steam-engine, the packing frame or ring D, in combination with the equalizing frame or ring B, the packing-groove c, packing O, springs E E, and steam-vents F F, &c., substantially as described, and for the purpose as set forth.

JOHN BOOTH.

\Vitnesses:

J. G. LIGHTFORD, JOHN GOODNOUGH. 

